Enabling gmail chat

Yesterday one of my friends wanted to chat with me very urgently. He wanted me to use gmail chat. When i logged into my gmail account i found that i am logged out of chat and gmail wanted me to re-login to chat. I tried clicking "enable chat" link on the bottom, moved to older standard version , altered all settings etc but i could nt fix the issues. After a long try i could fix the issue by clearing all google cookies in my browser. If anyone experience the same issue please follow the following method. In firefox go to tools --- options --- privacy --- show cookies --- select the google cookies from the list --- Remove cookies.